What are the 'correct' details that you have entered? Are you on Infinity (VDSL) or standard broadband (ADSL)?
Non-standard G.vector (G.993.5). had to be disabled for me or connection broke
Im on BT's Fibre 2 plan
My ping times to London servers aren't too bad anyway (im about 20miles away)- they range from 8 to 15ms